Helmholtz Coils for Production of Powerful and Uniform Fields and Gradients

The magnet is an air core and water-cooled massive Helmholtz type with rectangular cross section. It consists of a field coil 10 cm in mean radius which can produce 35 000 oersteds at a power of 1700 kw with a uniformity of about 10 ppm at the center within a region of 10 percent of the mean radius, and a gradient coil 5.2 cm in mean radius which can produce a gradient of 100 oersteds per cm at a power of 2.5 kw with a uniformity of about 140 ppm within the same region. The fields and gradients are separately controlled.